PUT THE COOKIE DOWN. It sounds like a line from Arnie, but in fact it's from some of the World's top researchers and Doctors. From the Daily Mail,BBC to the Independent the campaign for 'Action on Sugar' is in full force. But how much of a problem is sugar? It surely can't be that bad, after all the European Food Standards Agency (bizarrely) recently 'certified' it as healthy. On the other hand would we notice at all if it wasn't even in our diets?
The bitter truth
Much of the research against fructose stems from Dr Robert Lustig particularly his lecture entitled 'The bitter truth'
At 90 minutes it is very long, but is very compelling. The main snapshots are that while glucose can be absorbed and metabolised by every single cell in the body for energy production, fructose is only metabolised in the liver. This leads to formation of pyruvate and then citrate that is converted to fat and VLDL cholesterol. It's worth noting though that a lot of the metabolism research is from RAT studies so this is not definitive. It's quite clear though that the only substances that are 100% metabolised by the liver, the quality control organ of the body, is those it needs to break down, like fructose.
Sugar is bad for the brain
If you can't get through the day without cake and 'full fat' fizzy drinks then not only are you increasing your waistline but also dumbing down. For most people, we need to think clearly to be on the ball to be good at our jobs. Too much sugar can destroy your learning and working memory (1). It was reported in a study from UCLA, too much sugar caused a decline in cognitive function with diets high in fructose while low in omega 3 fatty acids (2). Increased consumption of fructose has been associated with lower cognitive function (3)
Sugar high drinks are the main issue, causing a quick surge of sugar into your blood stream, which then causes insulin release followed by a blood sugar crash then you feel the need to eat again. This will lead to poor productivity needing to eat or top up every couple of hours. Fructose will also make you feel more hungry as it slows down the release of a hormone called Leptin that tells your brain (hypothalamus) you are full. Without this signal the brain does not signal satiation (4), therefore you just eat more.
Sugar will make you eat even when you aren't hungry
Even looking at sugary snacks can trigger the reward centre of your brain into action. We've all had that internal monologue 'How good does that brownie/cake look?'. I don't think anyone has looked at a cabbage and thought the same. So you want to eat when you don't need to and have given your body time to break down what it has already is metabolising, a true state of excess calories.
Once sugar hits your tongue it causes a release huge amount of the feel good transmitter, Dopamine, to be released. This is what activates your sugar cravings, notice you'll want more and more. That's why it's easy to become addicted to sugar. I remember how much I craved a can of Coke EVERYDAY, I needed it! Glad I don't have that dependance or desire anymore.
Be more cultured
With over 100 trillion bacterium in our body our human cells are outnumbered 10 to 1. Most of them reside in our gut, therefore what ever we eat, they eat. Overconsumption of fructose leads to a shift in the microbiota metabolism. This alteration is hypothesised to lead to subsequent weight gain, as they release substances that can interfere with satiety levels, so we eat more (5)
Low carbohydrate diets can be healthier
Many people are still under the conception that without sugar they'll be hungry or devoid of energy. You've got to listen to your body, right? After consistently eating a lot of sugars and carbhydrodrates your brain thinks it needs more than it does. In fact you can be a lot more healthier with very little amounts of carbohydrates. You've heard of mineral, vitmain, fat, and protein deficiencies, but you'll never find carohydrate deficiency (not that I've found!). In one study comparing low carbohydrate vs low fat diets in men and women, both lost more weight & body fat in the low carbohydrate diets (6). While another study over a 6 month time period showed decreased LDL cholesterol & triglyceride levels, decreasing their heart disease risk (7,8). Most people on low carb diets don't have many problems with hunger compared to low fat (9).
It's all in the dose
There is no need to completely cut out all sugars from your diet. Like most substances we take into our body, the poison is in the dose.
But how much is too much? Researchers from University of Fribourg in Switzerland compared one group of 15 volunteers drinking 60g fructose in a drink compared to another 15 drinking 60g glucose. The result was that blood pressure levels were elevated only in the fructose group (10). That's about 5 apples, or just under 2 cans of coke.
Just eat real food...
...Not edible products. While the evidence is not fully complete on whether fructose has the all deleterious effects they are vilified for, it's clear that obesity is rising with our obsession for quick and easy food, unfortunately much of which advertised to children. What once was just used as a treat and special occasions is an everyday occurrence. Biggest change people can make is learn how to cook, and eat more fish, meat and veg and less processed food.